Door structure



Sept. 29, 1964 M. Mu ROSENFELD DOOR STRUCTURE I Filed Now :50, 1961INVENTOR.

MORTON M.RO$ENFELD ATTORNEY United States Patent Oflice Patented Sept.29., 1964 3,150,618 DOOR STRUCTURE Morton M. Rosenfeld, 271 MadisonAve., Mount Vernon, N.Y. Filed Nov. 30, 1961, Ser. N0. 155,990 6 Claims.(Cl. 109-1) This invention relates to a door structure, and moreparticularly, to a door structure which is designed to accommodate aportion of a ventilation system for an enclosure such as a bomb shelteror the like.

In accordance with the present invention, a bomb shelter or otherenclosure is provided with a pair of doors in series with one another.The outermost door is disposed in a manner so as to provide for thepassage of air therearound. The innermost door is sealed with respect toa door frame. The innermost door is provided with a removable filterthrough which air must pass in order to enter the enclosure. The filtermay be any one of a wide varity of commercially available filters whichis capable of filtering out air-borne dust.

Means are provided so that the filter in the innermost door may beperiodically replaced with a new filter in a manner which does notrequire the occupants of the enclosure to physically touch the filterbeing replaced. An accumulation chamber is provided below the doorstructure to receive replaced filters. The outermost door may be arcuatein transverse cross section thereby being capable of withstandinggreater pressure. Means are provided so that the outermost door offersflexible resilience to a blast.

It is an object of the present invention to provide a novel doorstructure.

It is another object of the present invention to provide a novel doorstructure having a pair of doors in series.

It is another object of the present invention to provide a doorstructure wherein two doors are disposed in series, with one of thedoors being sealed at its periphery to the door frame or the like.

It is another object of the present invention to provide a novelentranceway for a bomb shelter which provides means for filtering airentering the bomb shelter.

It is still another object of the present invention to provide a doorstructure for an enclosure which facilitates the entrance of ventilationair into the enclosure.

It is still another object of the present invention to provide atamperproof source of air for a bomb shelter or the like.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in thedrawings forms which are presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIGURE 1 is an elevation view of the outermost door disposed in adoorway of an enclosure such as a bomb shelter.

FIGURE 2 is a sectional view taken along the lines 22 in FIGURE 1.

FIGURE 3 is a sectional view taken along the lines 33 in FIGURE 2.

FIGURE 4 is a sectional view similar to FIGURE 3, but illustratinganother embodiment of the outer door.

FIGURE 5 is a sectional view taken along the lines 5-5 in FIGURE 2.

FIGURE 6 is a partial perspective view illustrating a manner in whichthe outer door may be latched to prevent forceful entry.

Referring to the drawing in detail, wherein like numerals indicate likeelements, there is shown in FIGURE 1 a portion of a bomb shelter or thelike designated generally as 10. The bomb shelter 10 may be anunderground enclosure, an aboveground enclosure, or an enclosuredisposed within the corner of a basement of a building.

The bomb shelter 10 will include a wall 12 which is upright with respectto a floor 14. The wall 12 and floor 14 are preferably made fromreinforced concrete or the like. A doorway 16 is disposed in the wall12. The doorway 16 extends upwardly from the floor 14.

An I-beam 18 extends along one side of the doorway 16. The flangeportions of the I-beam 18 are coextensive with the inner and outersurfaces of the wall 12. A C-beam 20 extends along an opposite surfaceof the doorway 16 from the I-beam 18. The =C-beam 20 is provided with aflange 22 extending toward the I-beam 18.

A door frame 24 is disposed around the doorway 16 on the inner surfaceof the wall 12. An inner door 26 is pivotably supported by the doorframe 24 for movement between an open and a closed disposition. The doorframe 24 is provided with a deformable seal 28 which cooperates with thedoor 26 in its closed disposition.

An outer door 30 is pivotably supported by hinges 32 extending from theI-beam 18. When moving from a closed to an open disposition, the doors26 and 30 pivot away from each other. The door 30 is provided with aplurality of spaced transversely extending reinforcement ribs 34. Aplurality of cylindrical casings 36 are fixedly secured to the innersurface of the door 30 at spaced points therealong. The casings 36 aredisposed one above the other adjacent the edge of the door 30 remotefrom the hinges 32.

A coil spring 38 is disposed within each casing 36. One end of eachspring 38 is secured to the casing 36. The other end of each springextends to a point so that it is in abutting contact with the flange 22.The springs 38 are of suflicient strength so that they act as a limitstop for the closed disposition of the door 30 during normal operationthereof. If the door 30 is subjected to a strong blast or otherwise isunduly forced inwardly, the springs 38 will permit the door 30 to moveinwardly to absorb the pressure. Hence, the springs 38 enable the door30 to offer flexible resistance when the door 30 is subjected to apressure greater than a predetermined amount.

One end of an L-shaped latch 46 is pivotably secured to the innersurface of the door 30. The other end of the latch 40 terminates in aclosed loop 42. As shown more clearly in FIGURE 6, the loop 42 may bepositioned to one side of a rod 44. The rod 44 extends from the flange22 in a direction substantially perpendicular thereto. The closed loop42 is adapted to selectively recieve a latch pin 46. As the door 30pivots about hinges 32 when subjected to pressure greater than apredetermined amount, the pin 46 will reciprocate along the rod 44. Theprovision of the pin 46 prevents forceful entry into the bomb shelter 10by unauthorized persons.

It will be noted that the periphery of the door 30 is spaced inwardlyfrom the doorway 16 and beams 18 and 20 so as to define a ventilationspace 48 therebetween. Hence, the chamber between the doors 26 and 30 isalways in communication with atmosphere. The door 30 may be providedwith a handle 53 to facilitate opening and closing of the same from aposition outside of the bomb shelter 10.

The door 26 is provided with an aperture 52 therethrough. A filter 54 isremovably disposed within a flange which defines the aperture 52. Abaflle 56 is supported by the door 26 in spaced relation thereto withthe baffle disposed over the opening 52. The balfle 56 may be made froma screen or other member which facilitates the passage of air to thefilter 54. A casing 58 is disposed on the outer surface of the door 26below the baflle 56. The casing 58 is provided with open upper and loweras ends. The lower end of the casing 53 is in line with a passageway 60.The passageway 60 provides communication with a chamber 62.

The chamber 62 is of suflicient size to accommodate a large number ofreplaced filters. As filters are replaced, they are caused to bedischarged into the chamber 62. When the bomb shelter It) is unoccupied,a lid 64 is provided for the passageway 69. As shown more clearly inFIGURE 5, the lid 64 is provided with outwardly extending flanges 66which rest on the floor 14. The lid 64 may be provided with a handle tofacilitate manipulation thereof.

When circumstances arise which require use of the bomb shelter It), theoccupants thereof will enter the same by opening door 30 and door 26.Thereafter, the lid 64 will be removed and positioned in any convenientlocation. The door 30 will be latched in a closed disposition asillustrated in FIGURE 3. Thereafter, the door 26 will be moved to aclosed disposition as illustrated more clearly in FIGURES 2 and 3. Afilter 54 will be located within the opening 52. Ventilation for thebomb shelter 10 is provided by means of the space 48 around the door 30.Air entering through the space 48 then makes a 90 turn and enters thebomb shelter 1th through the filter 54.

The filter 54 will filter out any air-borne dust in the air. Thecircuitous path for the air precludes the entry of beta radiation intothe bomb shelter 10. The door 30 or 30 prevents forceful entry into thebomb shelter 10 thereby making the filtered ventilation systemtamperproof. The arcuate nature of the door 32) assists in dispersingthe pressure of the blast. The filter 54 may be cleaned by directing astream of pressurized air through the filter toward the baffle 56. Anydust accumulated on the filter 54 which is blown off by the stream ofpressurized air will settle in the chamber 62.

The springs 38 act as a limit stop for the door 39 or 30 in its closeddisposition. The pressure wave of a blast will cause the springs 38 tocompress thereby allowing the outer door to absorb a substantial portionof the shock wave. As the outer door moves inwardly under the effect ofthe shock wave, it pivots about the hinges 32.

As illustrated, the doors are hatched to indicate that they are madefrom metal. It is within the scope of the present invention to providethe doors with a concrete liner having elements disposed therein whichare capable of providing high shielding against radiation.

The embodiment illustrated in FIGURE 4 is identical with the embodimentillustrated in FIGURES 13, 5 and 6 except for the details of the outerdoor Stl. The outer door 30 is identical with the door 36 except as willbe made clear hereinafter. An arcuate plate 68 is supported on theoutermost surface of the door 30. The side edges of the plate 68 are insliding abutting contact with the outer surface of the door 30. Guidepins 7t) on the door 30' extend into elongated slots 72 adjacent theside edges of the plate 68. As illustrated, the slots 72 extend inwardlyfrom a side edge of the plate 63.

The plate 68 is sufiiciently flexible so that it may be flattened whensubjected to sufiicient pressure. A pressure wave from a blast directedtoward the plate 68 will flatten the same against the door 30. In thismanner, the door 30' will absorb a substantial amount of the pressurewave. The remainder of the pressure wave will be substantially absorbedby compression of the springs 33. As the plate 68 flattens against thedoor 30, the peripheral edges of the plate 68 reciprocate toward theperipheral edges of the door 30'. Such reciprocation is guided by thepins 70 disposed in the elongated slots 72. After each pressure wave,the plate 68 will resume the disposition illustrated in FIGURE 4 due toits inherent resiliency.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim:

1. A bomb shelter comprising an enclosure having a doorway, an inner andan outer door in series in said doorway, a flange on said doorwaybetween said inner and outer doors for resiliently supporting said outerdoor, a chamber in a floor below said doorway, a passageway providingcommunication between said chamber and the space between said doors,guide means on said inner door for guiding replaced filters into saidpassageway, an aperture in said inner door, a replaceable filter in saidaperture, means providing communication beween the atmosphere and thespace between said doors, and means for enabling said outer door tooffer flexible resistance to a pressure wave.

2. A bomb shelter in accordance with claim 1 wherein said last mentionedmeans includes resilient springs having one end secured to said outerdoor, said resilient springs being in abutting relation with saiddoorway flange.

3. A bomb shelter in accordance with claim 1 wherein said last mentionedmeans includes a flexible arcuate member mounted on the outer surface ofsaid outer door in a manner so that said flexible member may becomeflattened under the effect of a pressure wave.

4. A bomb shelter in accordance with claim 1 including a lid removablydisposed over said passageway.

5. The bomb shelter of claim 2 including latch means for said outerdoor, said latch means consisting of an L-shaped bracket pivotallysecured to the surface of the outer door adjacent said inner door, saidL-shaped bracket having a perpendicular extension adapted to be placedflush with the surface of said flange facing said inner door, a latchpin, a closed loop integral with said perpendicular extension, said pinadapted to be placed through said closed loop, and a flange guide pinextending perpendicular from the surface of said flange adjacent saidinner door toward said inner door, said flange pin being in a positionwhereby said latch pin will ride therealong as said resilient springsare compressed by the movement of said outer door.

6. The bomb shelter of claim 1 wherein said guide means includes abaflle secured to the surface of said inner door facing said outer door,said baflle being secured to said inner door immediately above saidaperture, said baffle extending out of the surface of said inner door adistance greater than the thickness of said filter, said bafile havingan opening at the bottom thereof, and said guide means also including aguide channel mounted on said door immediately below said baflle, saidguide channel having a portion thereof spaced from the surface of saiddoor a distance greater than the thickness of said filter, said guidechannel having an opening at the bottom thereof immediately above saidpassageway.

References Cited in the file of this patent UNITED STATES PATENTS2,537,896 Hinton et al Jan. 9, 1951 2,704,983 Van Dronkelaar Mar. 29,1955 2,798,422 Bourque July 9, 1957 2,339,157 Schuster June 17, 1958FOREIGN PATENTS 14,848 Great Britain Nov. 16, 1886 808,939 France Nov.24, 1936

1. A BOMB SHELTER COMPRISING AN ENCLOSURE HAVING A DOORWAY, AN INNER ANDAN OUTER DOOR IN SERIES IN SAID DOORWAY, A FLANGE ON SAID DOORWAYBETWEEN SAID INNER AND OUTER DOORS FOR RESILIENTLY SUPPORTING SAID OUTERDOOR, A CHAMBER IN A FLOOR BELOW SAID DOORWAY, A PASSAGEWAY PROVIDINGCOMMUNICATION BETWEEN SAID CHAMBER AND THE SPACE BETWEEN SAID DOORS,GUIDE MEANS ON SAID INNER DOOR FOR GUIDING REPLACED FILTERS INTO SAIDPASSAGEWAY, AN APERTURE IN SAID INNER DOOR, A REPLACEABLE FILTER IN SAIDAPERTURE, MEANS PROVIDING COMMUNICATION BETWEEN THE ATMOSPHERE